Aristotle’s notion of substance presents various problems of interpretation. Many interpreters focus mainly at the notion of primary substance, especially with regard to the difference between how Aristotle defines it in Metaphysics VII and in the Categories. The present study aims at confirming mutual compatibility of these texts and touches also the problem of knowability of the primary substance. Translation: Lukáš Novák

The article offers a critical biography, description and characteristic of method, fonts and doctrine of Master Paul of Soncino († 5 August 1495), friar of the Dominican Order, in particular his Acutissimae Quaestiones Metaphysicales. The life and work of this philosopher falls within the ambit of Italian Thomism of the 15th century. Between his masters we commemorate Peter Maldura of Bergamo and Dominic of Flanders. His exposition of Aristotle’s Metaphysic proceeds from a peculiar synthesis of Arabic Commentator Averroes and Thomas Aquinas. Soncinas’ work and position was frequently discussed up to the 15th century.

Two kinds of individuals are distinguished: abstract and concrete. Whereas abstract individuals belong to our conceptual sphere, concrete individuals (i.e. particulars) individuate the world of matter. A subject inquiring the external world projects abstract individuals onto the concrete ones (i.e. pieces of matter). Our theory offers a solution to various ontological and epistemological puzzles concerned with individuals, e.g., the Ship of Theseus, Polish Logician, problems with reidentification, or proper names.

The genuinely Aristotelian conception of possibilia (possible non-existing entities) does not admit their own potency to coming-to-be (“objective potency”), nor, consequently, does it ascribe any kind of “weak” existence to them. Nevertheless we can (and need) admit possibilia as legitimate objects of rational discourse. In its concluding part this paper proposes a definition of the logically possible, as well as a definition of the ontologically possible (which is possible not only because its notion is noncontradictory, but also due to the existence of its potential causes).

The aim of the article is to critically assess the widespread surmise according to which Descartes was in certain important aspects of his thought infl uenced by Suárez’s Metaphysical Disputations. In the article this question is addressed with regard to the problem of the ontological background of the representational acts of a finite mind. Descartes’ position is reconstructed on the basis of an analysis of Meditation III and consequently of Descartes’ polemic with Johan de Kater in the First Objections and Replies; the reconstruction is accomplished by means of terms and concepts commonly used in the late scholastic thought of the end of the 16th century. An analysis of the key passage of Section 2 of Disputation 54 of the Metaphysical Disputations of Suárez (concerned with the distinction between extrinsic denominations and beings of reason) then shows, first, that Suárez’s position concerning the ontology of mental representation does indeed agree with that of Descartes, not Kater; second, that the implications of Suárez’s critique of certain theses concerning the identity of extrinsic denominations and beings of reason probably form an important part of the conceptual framework presupposed in the polemic between Decartes and Kater.

Aristotle’s subtle distinction between the forms of friendship and his concept of loving friend as one’s other self propose a solution to the fundamental objection to any eudaimonian theory of slavery, namely that friendship – as basically non-moral phenomenon – is but an egoistic device of one’s happy life. Aristotelian theorems are based on his concept of analogy and on a philosophically specific notion of “self”. Since both of these are rooted in Platonism, Aristotle has toevolve them dialectically in a critical distance to Plato. Still, his dialectical theory of friendship needs to be rooted not in metaphysics but in political theory after all. Political friendship as a utopian perspective taken by each of the citizens in their pursuit of a close relationship with any other indicates a notion of “infinity as perfection” which presents the decisive step beyond Plato and toward the later course of the history of philosophy.

The present paper deals with the notion of essence in Thomas Aquinas. Part 1 focuses on the main points of Aquinas’s doctrine of essence set out in his De ente et essentia, and especially on the concept of essence as the “form of the whole” and the concept of the “nature considered absolutely”. The comparison with the teaching of Aristotle and Aquinas’s Arabic predecessors in Part 2 shows that Thomas’s notion of essence is an innovative re-interpretation, which he largely owes to Avicenna, of the original Peripatetic doctrine. Nevertheless, it is shown that this re-interpretation is to be understood as a result of Avicenna’s and Aquinas’s effort to provide a consistent explanation of various statements in Aristotle’s writings, not always compatible with each other.

This paper investigates Ockham’s claim that there is a diversity of suppositions of a mental term. First, it summarizes the hitherto research in Ockham’s theory of concepts (understood as natural signs) and the theory of mental language ascribed to him (Part 1–2). Secondly, it describes his theory of supposition, focusing on the interpretation of this theory which describes it as a device for interpretation of propositions (Part 3). Thirdly, the paper examines the problems which arise from combining Ockham’s theory concepts and his theory of supposition (Part 4–7) – namely, the problems concerning the nature of mental proposition, the questionof mental syncategoremata, and of equivocation in mental language. Part 8 then reveals the absurdity of understanding the supposition of a mental term as an instrument for interpretation of mental propositions. Finally, I propose a new interpretation of the whole issue, based on Ockham’s early commentary on the Sentences (Part 9). According to this interpretation, the diversity of supposition of a mental term is not triggered by the need of distinguishing various meanings of a mental propositions, but by Ockham’s nominalistic theory of science.

The kalām cosmological argument for the existence of God proposed by W. L. Craig (in 1970’s) has been subject to much debate on all sorts of issues related to the existence of God and the beginning of the universe. The goal of the paper is to briefly evaluate several complex questions embraced in the argument in order to show the depth and strength of the argument, and to avoid oversimplification, which one can find in some recent publications. The argument as such does not rely on a single thesis or a theory proposed by a single author. The argument has such a support from different fields that its opponents would need to elaborate a theory with much more explanatory power than the most recent cosmological theories.

Opusculum insolubilium is an anonymous sixteenth-century British logical treatise dealing with the so-called “insolubles”, i.e. self-reflexive paradoxical propositions. It summarises the fundamental principles of the approach proposed by Roger Swyneshed in the fourteenth century, which became popular in the British academic circles during the fifteenth century. The present paper has two basic aims: to contrive a modern edition of this treatise which could be used fora further research in post-mediaeval scholastic logic, and to provide elementary information about its content and historical context.

The doctrine put forth by G. Frege and now almost universally accepted, according to which a predicate expressing a relative notion has to be supplemented by two (or more) subjects, in order for a statement to arise, appears to be a source of certain difficulties. In the paper, the author defends the view that this doctrine goes against our natural understanding of language, and shows that as soon as an attempt to determine the extension of such “relative” predicates is made, a contradiction in the doctrine is laid bare.

The article deals with various modal versions of the ontological argument from N. Malcolm’s to P. Tichý’s interpretation of Anselm’s second proof. Three key presuppositions of the modal proof are pin-pointed and examined. The principal problem with the proof seems to be the notion of necessary existence attributed to God. More precisely, the question is whether this is not too strong an attribute, for then there would not be a situation, i.e. a possible world, consistently thinkable which precludes the existence of God. However, this seems to be wrong.